1. Field of the Invention
The present invention relates to a method and apparatus for recording signals with a chart recorder and a device; more particularly, the present invention relates to a method and apparatus for recording signals with a chart recorder, and a fiber optics tube producing an electron beam which is simultaneously deflected both horizontally and vertically.
2. Description of the Prior Art
Devices and methods of this type are fairly well known. For example, U.S. patent application Ser. No. 1427/70 now U.S. Pat. No. 3,605,109 filed Jan. 8, 1970 is noted. The method and the device disclosed therein teaches a method and apparatus for recording signals on a record medium such as a photo sensitive paper by a fiber optics tube which sweeps only horizontally.
As mentioned above, a conventional chart recorder using a fiber optics tube records signals as dots or lines while scanning lines which are horizontally parallel to each other. Consequently, the dots or the lines do not connect to each other.
Whereas, the chart recorder recording method and device of the present invention employs a horizontal sweeping means and a vertical scanning means using a horizontal deflection yoke and a vertical deflection yoke on the fiber optics tube, the fiber optics tube has the vertical deflection yoke, too, in order to adjust for the vertical drift of the electron beam in the tube caused by the environmental magnetic fields, geomagnetism, heat drift of electrodes and/or the like.
A conventional chart recorder with a fiber optics tube uses the vertical deflection yoke only for adjusting for vertical drift. Whereas, the present invention uses the vertical deflection yoke for not only for adjusting for vertical drift but also for scanning signals vertically. The signals can thereby be recorded not "in one field" but "in two fields".
Hence, in this invention, a signal in one sampling or scanning can be recorded on a photo sensitive paper as a line which has not only length but also inclination; thus, one line in one scanning connects to the next line in the next scanning. Consequently, one connected line being bent at each connection can be obtained, which is very similar to the original signal wave.
Referring to FIG. 1, there is illustrated a fiber optics tube with a record medium such as a photo sensitive paper. A conventional chart recorder scans an electron beam only in the horizontal direction marked by line A-A' in FIG. 1, and the photo sensitive paper is intermittently driven vertically in the direction marked by arrow B in FIG. 1. Therefore, a wave illustrated in FIG. 2 as an example is recorded on the photo sensitive paper by the dots shown in FIG. 3. This wave in FIG. 2 is a sine wave, which is very simple to record. However, it is very difficult or impossible to determine the shape of a wave or waves on the paper in the case of a complicated wave or multiple waves. This is because it is very difficult or impossible to find which dot follows another dot.
In order to solve this problem, another chart recorder was invented, which is disclosed in the U.S. patent application Ser. No. 1427/70 now U.S. Pat. No. 3,605,109 as mentioned above, and a wave of which is recorded as lines on the paper as illustrated in FIG. 4. However, the lines are all horizontal and are not connected each other. Consequently, the recorded wave is not similar to the original wave as the recorded wave by the present invention is, which is illustrated in FIGS. 5 and 6. Since the lines are not connected to each other, it is impossible to figure out the natural shape of the recorded wave or waves even if the gaps between the disconnections are small as can be understood from the chart shown in FIG. 5, wherein the original sine wave in FIG. 2 and the recorded lines in FIG. 4 are illustrated together.
The present invention has changed the basic recording means from one dimension to two dimensions. Thus, the above mentioned problems in prior arts have been solved.